Occasionally older mobile devices or operating systems create issues for customers during the checkout process. Make sure your device’s operating system is updated to the most recent version available, then re-attempt checkout. If that doesn’t work, try checking out on another browser or device!
If that doesn't work, here are a few other things you can try that may help:
1. Using an incognito/private browser to access the site
2. Using a different web browser
3. Using a different device
4. Disable any pop-up/ad blockers for our site
If you've tried all these and the problem persists, or to report a specific issue, please submit a ticket here with as much detail as possible.